US-GLOBEC NEP Phase IIIa-CCS: Changing Ocean Conditions in Northern California Current-Effects on Primary Production and Salmon
J. Huyer, M. Kosro, R. Smith, P. Wheeler [All at Oregon State University]

Project Summary

We propose an interdisciplinary study of changing ocean condition in the northern California Current during the 6-year GLOBEC LTOP period, which encompassed an El Nino/La Nina transition, an invasion of Subarctic water and a shift in the climate regime of the North Pacific Ocean. Our work will focus on synthesizing multiple data sets that fall into three groups: in situ oceanographic data, coastal salmon survival data, and widely used indices of climate or environmental status. Our central goal is to learn how changes in water masses, currents, stratification, nutrient concentrations, etc., respond to climate forcing and in turn affect primary production and salmon survival. We will do this analysis for the 6-year GLOBEC LTOP period and for earlier epochs for which data are available. Our interdisciplinary team includes senior participants in the NEP Long Term Observation Program in the northern California Current region, and in complementary studies of juvenile salmon.

We will address four specific objectives: 1) to relate the changing in situ physical and chemical ocean conditions observed during the major climate events of 1997-2003 to primary production and salmon survival; 2) to determine whether in situ physical and chemical ocean conditions, primary production, and salmon survival in the upwelling domains north and south of Cape Blanco have similar internannual variability; 3) to determine whether seasonal averages and interannual variability of ocean conditions in the northern California Current system during the 1997-2003 epoch system were significantly different from earlier epochs for which historical data are available; and 4) to relate commonly used indices of ocean conditions to local in situ measures of the currents, water masses, nutrients, etc., which directly affect primary production and advection, and to search for improved indices and measures.

We plan a series of research tasks. For Objective 1, we will identify the characteristics, the cross-shelf transport pattern, and alongshore transport of upwelling source waters; related observed variation of ecosystem properties to the major climate events and to phytoplankton biomass and salmon survival; and compare biochemical ratios under different climatic regimes. For Objective 2, we will compare upwelling domains north and south of Cape Blanco in late summer and in early spring (a mid-summer comparison is now in progress); evaluate phytoplankton characteristics north and south of the Cape; compare interannual variability north and south of the Cape; and compare coho survival rates north and south of the Cape. For Objective 3, we will compare physical oceanographic data from the 1961-1971 and other earlier periods with the 1997-2003 period; study biological and chemical data from selected periods; and compare historical salmon survival data with oceanographic data. For Objective 4, we will compare indices in common use now (upwelling index, coastal sea level, MEI, PDO, etc.) with in situ measures developed from the recent GLOBEC data, and attempt to devise new indices or measure that are amenable to efficient monitoring. We will also collaborate with other GLBEC NEP synthesis teams that are analyzing associated data sets.

This synthesis of interdisciplinary oceanographic data with salmon survival and climate indices would advance our intellectual understanding of critical processes in coastal upwelling ecosystems. This synthesis will improve our understanding of the dynamic processes that contribute to statistical correlations between salmon survival and climate indices.

This interdisciplinary synthesis would have broad impacts on the future of ecosystem monitoring and management in the Northeast Pacific, and on future research in other coastal upwelling regions. Identifying a few in situ measures or parameters that are critical for primary production and for salmon smolt survival would make it feasible and efficient to use coastal observing stations to monitor the health of the upwelling ecosystem.

NSF Award Summary

The investigators will launch an interdisciplinary study of changing ocean conditions in the northern California Current during the 6-year GLOBEC LTOP period, which encompassed an El Nino/La Nina transition, an invasion of Subarctic water and a shift in the climate regime of the North Pacific Ocean. They will focus on synthesizing multiple datasets (in situ oceanographic data, coastal salmon survival data, and indices of climate or environmental status) to learn how changes in water masses, currents, stratification, nutrient concentrations, etc., respond to climate forcing and in turn affect primary production and salmon survival. The four specific objectives of the study are (1) to relate the changing in situ physical and chemical ocean conditions observed during the major climate events of 1997-2003 to primary production and salmon survival, (2) to determine whether in situ physical and chemical ocean conditions, primary production, and salmon survival in the upwelling domains north and south of Cape Blanco have similar interannual variability, (3) to determine whether seasonal averages and interannual variability of ocean conditions in the northern California Current system during the 1997-2003 epoch system were significantly different from earlier epochs for which historical data are available and (4) to relate commonly used indices of ocean conditions to local in situ measures which directly affect primary production and advection and to search for improved indices and measures. This synthesis of interdisciplinary oceanographic data with salmon survival and climate indices will advance intellectual understanding of critical processes in coastal upwelling ecosystems and improve understanding of the dynamic processes that contribute to statistical correlations between salmon survival and climate indices. This study will have broad impacts on the future of ecosystem monitoring and management in the Northeast Pacific, and on future research in other coastal upwelling regions. Identifying a few in situ measures or parameters that are critical for primary production and for salmon smolt survival would make it feasible and efficient to use coastal observing stations to monitor the health of the upwelling ecosystem.

This page was last updated on March 14, 2007.

Maintained by:
Hal Batchelder
College of Oceanic and Atmospheric Sciences
Oregon State University
Corvallis, OR 97331-5503
phone: 541-737-4500; FAX 541-737-2064